......DE....FRGB..IT......SE......................R0525549EUROPEAN PATENT APPLICATIONA319930421EP92112261.019920717enenen179125/9119910719JP19930421199316199302031993055 5G 01P 21/00 A 5G 01P 15/09 B 5B 60R 21/00 BdeBeschleunigungssensor mit Selbst-Test und dazu gehörige SchaltungenAcceleration sensor with self-test, and circuit thereforfrCapteur d'accélération avec auto-test, et circuit pour celui-ci4MITSUBISHI CHEMICAL CORPORATION01852042M 88 EP 1145-2, Marunouchi 2-chomeChiyoda-ku, TokyoJPOhta, Fumioc/o Yokkaichi div. of Mitsubishi Petrochemical Co.LTD 1, Toho-cho Yokkaichi-shi Mie-kenJPTanaka, Nobuo c/oElectronic prod.developmentcenter of Mitsubishi Petrochem.Co.LTD5-2. 2 chome Marunouchi Chiyoda-ku,TokyoJPMukasa, Yoshinao c/oElectronic prod.developmentcenter of Mitsubishi Petrochem.Co.LTD5-2. 2 chome Marunouchi Chiyoda-ku,TokyoJPGohkura, Akira c/oElectronic prod.developmentcenter of Mitsubishi Petrochem.Co.LTD5-2. 2 chome Marunouchi Chiyoda-ku,TokyoJPWalter, Helmut, Dipl.-Ing.00012611Aubinger Strasse 81D-81243 MünchenDEDEFRGBITSE19930421199316

This invention relates to an acceleration sensor device suitable for self-checking during vehicle driving and a self-checking circuit. Therefore, an acceleration sensor device suitable for self-checking during driving is obtained by a planar vibrator consisting of piezoelectric area having piezoelectricity and non-piezoelectric area having no piezoelectricity, a plurality of first electrodes provided on an upper face of said piezoelectric area of the planar vibrator, at least one second electrode provided on an upper face of said non-piezoelectric area of the planar vibrator, and a third electrode means provided on lower face of the planar vibrator.